1. Field of the Invention
The present invention relates to a method for stopping operation of a reactor.
Priority is claimed on Japanese Patent Application No. 2011-074245 filed on Mar. 30, 2011, the content of which is incorporated herein by reference.
2. Description of Related Art
In recent years, as a process for synthesizing liquid fuels from natural gas, the GTL (Gas To Liquids: liquid fuels synthesis) technique has been developed. This GTL technique includes the steps of reforming a natural gas to produce a synthesis gas containing carbon monoxide gas (CO) and hydrogen gas (H2) as main components, synthesizing hydrocarbons using this synthesis gas as a feedstock gas and using a catalyst via the Fischer-Tropsch synthesis reaction (hereinafter also referred to as the “FT synthesis reaction”), and then hydrogenating and fractionating these hydrocarbons to produce liquid fuel products such as naphtha (raw gasoline), kerosene, gas oil and wax and the like.
In the hydrocarbon synthesis reaction apparatus used in this GTL technique, the hydrocarbons are synthesized by subjecting the carbon monoxide gas and hydrogen gas within the synthesis gas to an FT synthesis reaction inside a reactor main unit that contains a slurry prepared by suspending solid catalyst particles (such as a cobalt catalyst or the like) in a liquid medium (for example, liquid hydrocarbons or the like).
Moreover, in the hydrocarbon synthesis reaction apparatus, since carbon monoxide is contained in a synthesis gas, metal carbonyls (such as an iron carbonyl and a nickel carbonyl) are easily produced inside a reactor. There is a desire to remove these metal carbonyls from the reactor when operation of the reactor is stopped.
As catalysts for removing metal carbonyls, for example, there are known those described in Patent Document 1 given below.